Highly dispersed uniform silver nanoparticles were prepared by reducing silver diamine ions [Ag(NH3)2]+ with D-glucose in the presence of a stabilizing agent. Along with the nature of the dispersing agent, the pH and the temperature of the reaction had the most pronounced effect on the reduction rate, the nucleation of the metallic phase, and ultimately the size and dispersion of the resulting particles. Through suitable manipulations of these parameters, it was possible to prepare uniform Ag nanoparticles ranging in size from 30 to 120 nm. A rapid and complete reduction of the silver species was possible only at elevated pH and temperatures above 50 °C. The reduction of silver diamine ions in these conditions caused the complete cleavage of the C–C bond, resulting in the release of 12 electrons per molecule of D-glucose. It was also found that the addition of ammonia to an already acidified silver nitrate solution leads to the formation of a much more stable and safe-to-handle diamine complex.

The diffusion behavior and phase equilibria in the Cu-Zn binary system were investigated using solidsolid and solid-liquid diffusion couples. Heat treatments at temperatures ranging from 100 to 750°C were performed and the samples were examined using optical microscopy, energy dispersive x-ray spectroscopy, and electron probe microanalysis to identify the phases and to obtain composition profiles. Solubility limits of both solid solution and intermetallic phases were then evaluated, and a forwardsimulation analysis (FSA) was applied to extract interdiffusion coefficients. The composition profiles from Hoxha et al. were also re-analyzed using FSA to obtain more reliable diffusion coefficient data without the assumption of constant diffusion coefficients for the intermetallic phases. A comprehensive assessment of the interdiffusion coefficients in three intermetallic phases of the Cu-Zn system was performed based on the results from the current study as well as those in the literature. Activation energies and Arrhenius pre-factors were evaluated for each phase as a function of composition. The fitted equations based on the comprehensive assessment have the capabilities of computing the interdiffusion coefficients of each of the phases at a given composition and temperature. Suggested modifications to the Cu-Zn binary phase diagram were presented based on the new experimental information gathered from the present study. A clear explanation is provided for the puzzling low Zn concentrations often observed in the Cu-rich fcc phase of Cu-Zn diffusion couples in comparison with the expected high solubility values based on the equilibrium Cu-Zn phase diagram.

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This paper will illustrate a manufacturing line improvement design. The company which will implement our design is Jamjoom Medical Industries (JMI), a mid-size manufacturing company specializing in medical disposables. JMI is challenged with meeting the increased demand for their products and surpassing their competition. JMI sees these new challenges as an opportunity to re-evaluate the current situation and potentially increase the company's profitability. In order for JMI to accomplish this, a re-design (JMRD) of its manufacturing process is required. This project evaluates alternative designs that will supplement the current processes. JMRD focuses on the manufacturing method of the stop cock, a product that utilizes all facets of the plant. The results gathered from the analysis offer recommendations for changes to be implemented within the manufacturing process of the stop cock as well as other products. A simulation model of the manufacturing process is developed using Rockwell Arena software. The control variable in this re-design process is the product type. The simulation provides evidence of theoretical improvements including increased overall throughput and decreased number of defective units. Each design alternative will be evaluated by cost, performance, and maintainability. In support of the decision process for implementing changes, the improvements discovered in simulation are evaluated with a cost-benefit analysis. The following improvements are considered: automation implementation and statistical sampling of quality. A trade-off analysis will be done to allow our team to provide the decision makers with the best alternative that meets their requirements. Multiple alternative manufacturing product line designs are being evaluated and the analysis results are described.

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The life of a steel bearing component can be strongly influenced by the quality of the bulk material. The shape, surface, and internal structure of the component can be affected by the upstream steelmaking processes. The steel material must positively affect these characteristics through resistance to distortion and superior surface quality and internal cleanness. The TimkenSteel Faircrest jumbo bloom vertical continuous caster was designed to meet these high standards for the production of high-quality bearing steels. Improved segregation symmetry through the implementation of dynamic mechanical soft reduction and controlled cooling has resulted in customer testing to similar levels of finished product distortion as the bottom poured ingot product. The vertical nature of the machine avoids any bending or unbending strains and stresses that are placed on the surface of the curved cast product, and uniform heat extraction is more easily achieved. The straight shape of the strand also provides a greater potential for inclusion removal by flotation without producing any localized inclusion distribution such as an increased inner radius concentration often found in a curved machine cast product. Significant resources were dedicated to developing a unique and robust tundish design through physical and computational modeling efforts. The tundish produces consistent quality characteristics across all three strands and manages steady-state and transitional operational practices while incorporating a sealed inert tundish atmosphere to minimize reoxidation for increased levels of cleanness. The customized features of the machine have led to rapid qualifications from demanding bearing and gear customers using various testing methods, and quality levels have met or exceeded the TimkenSteel quality expectations.